


Monster Biology- Volume 2

by FanGirlStephie



Category: Undertale (Video Game)
Genre: Gen, all of my headcanons of how skeletons work as a species, i just wanted to write it as if it was in a book, i think about stuff i like... a lot, long story, not actually a sequel, sex is mentioned in a purely scientific way
Language: English
Status: Completed
Published: 2017-08-01
Updated: 2017-08-01
Packaged: 2018-12-09 22:39:49
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,458
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/11678544
Author URL: https://archiveofourown.org/users/FanGirlStephie/pseuds/FanGirlStephie
Summary: Have you ever wondered how the skeletons in the Undertale world work as a species? I have, a lot. So I wrote all of my ideas in this. I tried to write it in a way where it doesn't have to be just an Undertale thing if i wanted it to.I know its really long, but i have a lot of ideas. These are all of my personal ideas. If you have different ideas, that is fine ^^ I'd love to hear about them. And if you like my ideas and like to adopt as your own headcanon/s that is perfect fine as well.





	Monster Biology- Volume 2

Monster Biology- Volume 2 Magic Based Monsters

Chapter 2- Skeletons (Monstrum skeletus)

**Bones**  
Skeleton monsters are completely composed of bones. These bones are the only organic part of this species. Most commonly, skeleton monster bones are white in color. But it is possible for skeletons to have different colored bones. Most commonly black or a shade of red or brown. Bones can also turn a different color with age. Some skeletons “blacken” or “rust” with old age. This is when the bones of an older skeleton get a gray or red tint to it.  
Similar to many other monsters, skeleton monsters are “humanoid” in shape. This means they are bipedal and generally are the same shape as humans. Some monster scientists have theorized that humans and skeleton monsters may be more related than we currently think. But these theories have not yet been touched upon and are still just theories.  
Skeleton monster bones have thin hollow “vessels” running through the bones. The bones of a skeleton monster are held together with magic. The magic passes through the vessels from the soul to the entire body on a microscopic level. It is invisible to the naked eye. The bones also have bone marrow in them. These produce blood, which is transported with help from the skeleton's magic. Since they don't have physical hearts, the circulatory system of a skeleton monster goes through their souls.  
Some skeletons have a skull with a lower jaw that disconnects. This is normal as their jaw is held together with magic like the rest of the bones. Other skeletons have both the upper and lower jaw together as part of their skull. This is also normal as they do not need to “open their mouth” to talk or eat. Food passes through the spaces of the teeth using magic.  
Since the bones are held together by magic, the bones can also detach from the skeleton harmlessly. The skeleton's magic is not interrupted from their microscopic path through the bones. So when a skeleton detaches any of their bones, they can still feel anything that happens to said bone. They can even harmlessly take off their head from their neck bone.

**The Soul and Magic**  
Due to skeleton monsters not having any organic parts, except for their bones, all functions are controlled by magic. Their soul controls their brain and heart functions, unlike organic based monsters. On a microscopic level, the magic travels from their soul to the rest of the body. Providing movement, blood and magic flow, digestion, and brain functions. Besides this, skeleton monster souls are the same as general souls of monsters. Magic may also need to be discharged for various reasons. More about magic discharge in later sections.  
Skeleton monster magic, like some other magic based monsters, has different colors. There are theories that these colors match human traits. But no testing has been done on these theories as of yet. Colors of their magic can even be different shades of the same color. Some believe that a skeleton child's magic color reflects one or both parent's magic color. But multiple surveys have showed that this is not always the case. If the two colors are “mixture compatible” then they may mix together to make a new color. But if they are not, then the child's magic color may be a random color or a related color. But even mixture compatible parents might not have a mixed color magic child. Studies have shown that 51% of the time, the child's magic will be mixed of the two colors.  
Mixture compatible colors of skeleton magic currently is as follows: any combination of blue yellow and red, white and any color, any color with black, pink and purple, green and yellow, orange and yellow, red and purple, blue and purple, green and blue, red and orange. If you have a question of your magic color and if they are mixture compatible, please contact your local monster doctor.  
Like all monsters, skeletons can use basic fire magic. Skeletons are also frequent users of “blue attacks”. Meaning in battle, they use magic to turn a soul blue. Turning a soul blue manipulates it's gravity and causes it to be heavy. Or they use magic to summon blue colored bone attacks. Blue bone attacks can only be passed by if one does not move. All bone attacks are created from magic. More about blue souls and blue attacks can be found in soul and attack specific textbooks.

**Eye Lights**  
Skeletons do not have organic eyeballs. Their eyes are created from their magic in a form called “eye lights”. Not all skeletons have eye lights. But those who do, eye lights as usually small white circles. These circles are purely aesthetic and not needed for sight function. Sight is provided by their soul magic, around the entire inside area of the eye socket. The eye lights are mostly to show expressions and convey feelings.  
Another way skeleton monsters convey feeling is “eye glowing”. This is when inside or around the eye socket of a skeleton glows with colored magic. The color of magic can be different and not all skeletons are the same. The color that glows is most commonly the color magic of the user. But in some cases it can be two colors at the same time, switching or half and half.

**Digestion**  
Like with all monsters, magic is restored by consumption. A skeleton needs to eat to restore their magic. For magic based monsters like skeletons, it is extremely important for a skeleton to eat on a regular basis. Information about if they don't eat and what could happen is in the section the next section.  
Digestion for a skeleton happens on a microscopic level. Food goes in, or through, the mouth and gets chewed up. Saliva like magic coats the food and immediately begins the digestion process already. The skeleton then swallows, moving the coated chewed food down the neck bone. The magic coated food gets more and more broken down as it travels, until it's invisible to the naked eye. Then the magic transports the food energy to the soul. From the the soul, the energy gets transported to wherever it's needed, or stored as excess magic.  
When there is more energy than needed, the excess will go into magic reserves. The magic reserves are located in the soul. When there is too much magical reserves, discharge of the excess will be needed. Discharging of the excess magic can be done in multiple ways. Whether that be up through the mouth (“throwing up”), discharging through ejaculation, discharging through “urination”, dripping straight from the bones, or even dripping straight from the soul.  
Urination is not typical organic urination that one may think of. The magic that is dispelled during “urination” is just pure excess magic. An “ecto body part” is formed to discharge the magic. More about ecto biology in a later section.  
Not all skeletons wish to discharge their magic through any means. There are also some who have problems with storing magic. A skeleton can simple use a lot of magic in that moment is get rid of the excess magic. Summoning a lot of attacks, but not in battle, etc. There is also medication one can take with a doctor's prescription.

**Diseases, Disorders, and Conditions**  
Skeletons are known to be very resilient, having very good immune systems, and do not get diseases often. But there are some skeleton specific illnesses. Please contact your local monster doctor for more information about any of these illnesses.  
Brittle Bones, also known as Osteoporosis, is something that a skeleton may develop with older age. The bones are very fragile and can break easily but heal slowly. This is caused by a combination of poor health, low magic production, the passage of time, and maybe even genetics. Some skeleton children can simply be born with fragile bones. Those with Brittle Bones must be very careful not to cause any breakage of their bones.  
Magic Production Disorder, also known as MPD, is referred to as “having a weak soul” in society. But this isn't quite the case. Those born with or develop MPD don't have a “weak soul”, there is simply an issue with magic production in the soul. MPD can also be a symptom or the cause of other illnesses. There are devices that can test the magic production levels of a monster.  
A variation of MPD is Magic Storage Syndrome. This is when something causes the skeleton to not store excess magic in their soul. Even though the skeleton eats as much or as little as they want, all excess magic is immediately discharged instead of stored. Currently it is still unknown at the time what exactly causes this to happen. It is also unknown if this is genetic or not. No consistent results have been recorded as of yet.  
Socket Syndrome, or Closed Socket Syndrome, occurs when at least one eye socket does not open during the time of childhood when it's supposed to. Skeleton children are born with their eye socket's closed. So that the eye socket lid bones can take the time to harden before being used. Skeleton babies are born with “soft bones”, meaning they are not at the hardness as older skeletons. So sometimes a skeleton baby's eye socket lid will not open. Surgery is possible in some cases, but not recommended in case of damaging the eye light magic and causing permanent blindness.  
Eye Light Blindness, also simply referred to as blindness, is when the eye light magic of one or both eyes does not work for various reasons. This may be from birth, an accident, low magic production, etc. Those with Eye Light Blindness can still have simple eye lights, but is purely for show and not actual use. But they will not be able to eye glow in that eye at all. This can lead to emotional problems and even mental disabilities.

**Genders of Skeletons**  
Skeleton monsters do not have set genders. A skeleton's entire genitalia is created by magic (ecto biology). So a skeleton can summon whatever gender they please with magic. Gender is completely feeling based. If the skeleton feels more like a male or female, they will refer to themselves as such.  
There are some theories that the shape of the pelvis and rib cage are different for skeleton genders. But studies and surveys have found that monster skeletons vary too much to confirm this theory. Monster skeleton shapes and sizes are very different from one another.  
It is theorized that the magic signature of the individual skeleton tells which gender is more dominant. Many skeleton parents have claimed this when Checking their children. There is no scientific link between the magic signature and gender identity as of yet. But it's generally accepted as truth by society. Some others believe that the first ecto genital a baby skeleton summons is their “dominant” gender, but this is not always the case.  
Since skeletons are only bones and magic, there is no flesh. So any skeleton can theoretically get pregnant and give birth. The opening of the pelvis is usually wide enough to push a skeleton baby out. But there are some cases where the pelvis is too narrow. In that case a type of c-section is available to cut into the ecto body and get the baby/s out.

**Skeleton Monster Terminology**  
Cemetery- A group of monster skeletons are called a cemetery.  
Grave- More that two skeleton babies being born at once is called a grave.  
Blacken- A gray tint to the bones, developing in old age.  
Rust- A red or brown tint to the bones, developing in old age.  
Eye lights- Circular lights inside the eye sockets that provide expression.  
Eye glow- When the eye lights/sockets glow a particular color magic to express feelings.  
Ecto anatomy- A physical manifestation of colored magic, semi-transparent around the bones of a skeleton to appear like the flesh body of a human.  
Soft bones- The bones of a skeleton baby, which is soft and fragile.  
Chirping- The noises a baby skeleton makes after it is born up to about 1-2 years old when they switch to typical baby talk.  
Baby bones- This is to describe the time from when a skeleton is born to about 5 years old.

**The “Ecto Body”**  
Skeleton monsters are capable of using their magic to form around their bones like flesh. This physical manifestation of magic can appear as anything. Most commonly, skeletons use this ecto magic to create genitals. The genitals are pure magic and only created to discharge magic or urinate. Ecto genitals also have the ability to detach from the bones. Skeletons are also able to summon genitals already detached. Overall, any body part or shape can be manifested with magic.  
Mother skeletons will use this ecto magic to form human-like breasts. They will then feed their babies magic that is specifically created for their skeleton babies. They can summon more that just two, also. Typically they summon enough ecto breasts to feed all, or nearly all, of their babies at the same time. The father skeleton can do this also and is highly recommended to do so. Feeding skeleton children this way is known as a great bonding experience and helps with the baby's emotional development.  
Most commonly, skeletons will only form ecto body parts below the neck bone. From the collar bone on down. The ecto body is most commonly human-like in appearance and shape. Some other very common shapes are; tentacles, tongues, animal-like male genitals, and even tails.

**Reproduction and Pregnancy**  
Skeleton monsters use magic in order to reproduce. Skeletons can reproduce any time and are not limited to any breeding season. Skeletons can go through a kind of “heat”. But these are not a typical heat cycle and only happen during certain situations. More about heats in the next section.   
The more common way to reproduce, and more likely to result in pregnancy, is what's referred to as “soul sex”. This is when the souls of two monsters, outside the body, touch together and share their magic essence. The “dom soul”, or soul that is more dominant, will share its magical essence with the “sub soul”, or soul that is more submissive. The soul of the sub skeleton will use the magic of the other to create a new soul. But sometimes both skeletons can get pregnant at the same time.  
Skeletons can also reproduce in a traditional fashion. One will be the “male” and one will be the “female” (or male if preferred). They engage in intercourse and the “female” skeleton will form a ecto womb. The “male” skeleton ejaculates into the “female”. Then both magic essences will mix together and create a brand new soul. Depending on the amounts of magic the two skeletons produce during mating, any number of new souls will be made. Any accidental pregnancies are usually caused from soul sex, the skeletons not knowing it causes pregnancy.  
When the souls are made, they will stay in the “stomach” area. This area below the rib cage and above the pelvis is empty, perfect for developing skeleton babies. An ecto belly will be formed immediately to keep the new developing soul/s protected. The soul/s start of very small, sometimes not even noticed by the pregnant skeleton. The soul/s will continue to grow for the next few weeks.  
Skeletons are not pregnant for as long as humans are. Skeletons typically are pregnant for about 30 weeks. The first month (usually 5 weeks) are for the development of the soul, its magic, and magical functions. The rest of the time is for the bones growth development.

**Birth**  
Skeletons have magic based live birth. The pregnant skeleton will push each baby out through their ecto body. The skeleton does feel a lot of pain since the ecto magic is tied directly to their soul and is very sensitive. But every skeleton is different and so their labors are all slightly different.  
Skeleton birth is usually quick, depending on the number of babies. If a skeleton can't get to a hospital to give birth, they must make sure they are on something soft. At home this could be a bed, or pile of blankets and pillows.  
Once the babies are born, the ecto body will disappear and the ecto breasts should appear. Some do take longer time than others, and if it does not disappear, please contact a monster doctor immediately. The “mother” skeleton should eat right away after giving birth. They need to begin producing magic to feed their babies as soon as possible.

**Heats**  
Heats for a skeleton monster is not a true heat. A skeleton heat only occurs during certain situations. They only last for a few days to a few weeks. During this heat, a skeleton will have an overwhelming need to eat a lot, and then mate for days after. They usually eat a lot to build up as much magic as possible for the constant mating that will occur. A lot of magic is used during mating.  
These skeleton heats tend to occur during hard times with low population and birth rates. They also tend to occur during or after wars and big battles. But basically, when the population of skeletons are low, heats will begin to occur. Scientists have theorized this is a natural instinct in the skeleton soul to keep the species surviving.  
But records have shown that places that are poor for the survival of skeletons, even with the heats, not many skeleton children tend to survive. Even when a big grave of skeletons are born, not many survive if the area is not that suitable for skeleton monster survival.

**Skeleton Babies**  
Skeleton babies are born with soft bones, eyes closed, and about 18 inches long on average. They have a natural instinct of knowing who and where their parents are. Skeleton babies can sense the soul of their parents. They quickly learn who their primary caregiver/s are. Starting at birth, skeleton babies “chirp” instead of crying. But this sound is called a “cry” or “crying” sometimes. The chirping is really just the long e sound and not actual bird chirps.  
Skeleton babies have different distinct chirps for different things. Skeleton parents can usually pick up on these chirps nearly right away. But sometimes it does take time to learn what exactly your baby wants. Skeleton parents often begin talking to them and responding to their chirps when they learn what the chirps mean. This is highly recommended for skeleton parents to do.  
Eye glowing is very calming for a skeleton baby and child. Before they are able to open their eyes, skeleton babies will often glow their soul in response to eye glowing. Skeleton babies also glow their souls when inside the womb or ecto belly, especially when their other parent is around. When they do open their eyes, eye glowing is a very frequent thing. But it's not always when a skeleton baby feels a particular emotion, sometimes it's random.  
Skeleton children are quick to learn to crawl, but slow to learn to talk. This is due to lack of lips and lack of a tongue (for skeleton babies). Skeleton babies are still developing their magic and the bones are still hardening. So skeleton babies are fragile in nature.  
A skeleton baby is still getting used to its magic. So they often are a bit unstable. They will summon an ecto body part at random, or will use blue or any magic at random. After they open their eyes, their eye lights may even go on and off, or change color, at random as well. 

**Other Information**  
Skeleton monsters are very adaptable as a species. They are also very persistent as a species and always find a way to keep going. Despite being known as more weaker of a monster species, and being known to be fragile as a species also. Skeletons are actually really durable, despite a naturally sensitive nature. Skeletons are known to be very connected to their world around them and their loved ones.  
Skeleton monsters also are known to have the most inconsistent stats. There are very strong skeletons with very high stats, and there are skeletons with extremely low stats. And every stat in between. Skeletons are known as “the snowflakes of monsters” cause of how it seems no two skeletons are the same.  
Skeletons are also very intelligent monsters. They seem to have no limit to their capacity of learning. There are some who claim skeletons even have “special abilities”. But nothing has been confirmed of this and it is merely just rumor.


End file.
